Carton



R. GUYER et. 3 M50 CARTON llnll ...|.lllllllllllllllll ill Filed July 3l, 1946 Jwmntoz a@ @gg W mm'? Patented Oct. 3, 1950 CARTON Reynolds Guyer, St. Paul, Waldorf Paper Products Minn., assigner to Company, St. Paul,

Minn., a corporation of Minnesota Application July 31, 1946, Serial No. 687,283

My invention relates to an improvement in cartons wherein it is desired to provide `a carton structure which may be effectively sealed.

Rectangular cartons are usually provided with closing flaps on at least one end thereof `which may be folded into superimposed relation to form an end seal. One end of such cartons can usually be tightly sealed over a mandrel inserted into the carton. In view of the `presence of the mandrel, sealing pressure can be applied to press the ilaps ilrmly together. However, it has been difficult to seal the otherv ends of these cartons as the contents of the cartolrwill usually not resist external pressure. Two short Ilaps on two opposed Walls are usually folded into coplanar relation, and flaps on the remaining opposed walls are folded over the coplanar ilaps and sealed thereto. When the coplanar naps are moistened with adhesive they have a tendencyto` curl down into the carton. External l pressure against the closure tends to accentuate this tendency of the inner flaps to curl. l l

It is the object of the present invention to provide a flap structure which is capable of withstanding external pressure. When applied to the opposed flaps, ilrst folded into coplanar relation, the tendency of these flaps to curl into the interior of the carton is also obviated. As a result a more effective seal can be accomplished.

It has usually been considered impractical to adhere two scored carton surfaces together with the scores in registry and to"fold the double thickness portions about the common line of fold. When two such surfaces are folded in unison there is a tendency forthe two plies to separate as the outer ply must stretch to some extent or the inner ply must compress together to some extent at the line of fold. Accordingly where carton walls have been formed of double thickness it has been usual practice to either terminate one thickness of the material at the line of fold, or else to leave the two plies unadhered on one side of the line of fold to permit relative sliding movement. I have found, however, that this previous difiiculty may be used to advantage in overcoming the difficulty in sealing carton closing naps together on the last sealed end of a carton.

A feature of the present invention lies in the :revision of a carton having two opposed side valls of double thickness and in forming closing laps on these walls which are also of double hickness. Each of the walls is provided with v score line, which score lines are adhered sub- 2 Claims. (Cl. `22S-43) stantially in registry. This double thickness of the ilaps at the score line tends to resist the force tending to fold these flaps into coplanar relationship. As a result the ilaps have a tendency to raise or to straighten out relative to the side walls rather than to fold down into the carton when adhesive is applied thereon or when external pressure is exerted against the flaps.

l A feature of the present invention lies in providing a carton having a pair of` opposed flaps to be folded into coplanar relation and to form these flaps of double thickness material on both sides of thescore line connecting the aps to thecarton. The score lines of the individual layers of stock are individually formed. As a result considerable force is required to fold these flaps into coplanar relationship and as a result these flaps are capable of resisting pressure exerted against ilaps overlying the coplanar flaps to produce aneifective seal. l

`These and other objects and novel features of my invention will be more clearly and fully set forth in the following specification and claims.

In the drawings forming a part of my specification:

Figure l is a diagrammatic view of a carton blank showing my new. design.

Figure 2 is a perspective view of the end of my carton before the sealing operation of the last carton end.

Figure 3 is an elevational view of my carton partly in section showing the double thickness flaps folded into coplanar relationship.

Figure 4 is a view similar to Figure 3v showing the carton completely sealed.

The carton A, which is illustrated in the drawings, is of a type usually known as a. Britewood Carton. This type of construction is employed because of the fact that two opposed walls of wall panels I3 and i4. The front panel i3 is connected along parallel fold lines I5 and I6, preferably at right angles to the fold line il to side wall panels I1 and I9, respectively. The rear panel Il is connected along fold lines 2li and 22 preferably in alignment with the fold lines I5 and I6 to side wall panels 23 and 24.

'I'he side wall panels Il and I 9 are connected along fold lines 25 and 2B, respectively, to side wall naps 2l and 29, which connect the bottom wall I0 to the side walls of the carton. 'Ihe side wall panels I1 and I9 and the front panel I3 are connected along a common fold line 30 to end closure naps 3|, 32, and 33, respectively. The side wall panels 23 and 24 and the rear wall panel Il are connected along a common fold line 3l to sealing naps 35, 33, and 31, respectively.

In forming the carton A the front and rear wall panels I3 and Il are folded into right angular relation to the bottom III so that the side wall panels I1 and 23 overlap and the side wall panels I3 and 2l overlap. Adhesive is applied between the panels I1 and 23 and between the panels I3 and 2| to hold the side walls in right the front and rear walls I3 21 and 29 are also folded adhesively to the exteriorly angular relation to and Il; The naps horizontallyand are sealed bottom panel Il either interiorly or thereof.

The adhesive securing the side wall panels I1 and 23 together extends between the flap 3l and the ilap 35 so as to adhesively secure these ilaps together. Similarly adhesive is applied between the ilap 32 and the flap 35 to adhesively secure these flaps together. As a result not only the side walls, but two of the end closing flaps are.

of double thickness.

The score line 33 registers with the score line 3l, or substantially registers therewith to permit the folding of the double thickness aps along a common line of fold.

In sealing the carton the double thickness ilaps are folded as illustrated in Figure 3 into coplanar relationship. Because of the connection between the two thicknesses of material on both sides of the common line of fold, there is considerable resistance to the folding of these iiaps. In folding the double thickness flaps it is necessary that the outer plies 35 and 36 stretch somewhat adjacent the line of fold or that the carton material between the inner plies 3| and 32 compresses somewhat at the line of fold. As a result there is a decided tendency for the folded flaps to fold into their original upright position and considerable pressure is required to fold them beyond the horizontal position shown in Figure 3.

Adhesive is applied either to the upper surfaces of the naps 35 and 38 as they appear in Figure 3, or to the under surface of the next adjacent ilap 33 so as to adhere these flaps together. Adhesive is also applied between the flaps 33 and 31 to adhere these flaps together. The tendency for the inner flaps to curl into the carton when moistenedwith adhesive is greatly reduced or obviated and this tendency is opposed by the greater tendency of the double thickness ilaps to fold into upright vertical position. Furthermore considerable external pressure can be appliedto the flap 31, tending to seal the various flaps securely together.

It will be noted that the flaps 3l and 32 are slightly shorter than the flaps 35 and 36 to which they are connected. This structure is followed in order to insure the proper meeting oi' the ilaps at the center of the carton, but is not essential. Furthermore, while I have shown the shorter flaps 3| and 32 connected to the side wall panels I1 and I3, obviously the other naps 35 and 35 could be shortened'to lie inwardly of the longer ilaps 3| and 32. I have further described the panelv I3 as comprising the front of,

the carton and the panel I4 as comprising the back of the carton, but this arrangement is merely for the purpose of convenience as any of the walls of the carton could be considered the front thereof.

In accordance with the patent statutes, I have described the principles of construction and operation of my carton, and while I have endeavored to set forth the best embodiment thereof, I desire to have it understood that obvious changes may be made within the scope of the following claims without departing from the spirit of my invention.

I claim:

1. A carton comprising a series of carton walls connected together, and closing iiaps foldably connected to said walls and foldable into superimposed relation, two opposed of said flaps on two opposed of said walls being foldable into superimposed relation and the remaining ilaps being foldable thereover, said two opposed walls comprising two thicknesses of carton stock, said double thickness carton stock extending on both sides of the line of fold connecting said two opposed flaps to their respective walls said two opposed flaps and their respective two opposed walls being secured together throughout their opposed faces on both sides of the line of fold.

2. A carton comprising a series of side walls foldably connected together, two opposed side walls being formed of two panels extending throughout their width in surface contacting relation and adheredtogether throughout their length, each of said panels having an end flap thereon connected thereto along registering fold lines, said flaps on said panels being adhered in surface contacting relation, said flaps being arranged in coplanar relationship, and closing aps on the remaining side walls folded over said first mentioned closing flaps and adhered thereto to form a carton closure.

REYNOLDS GUYER.

REFERENCES CITED The following references are of record in the 1 le of this patent:

UNITED STATES PATENTS Number Name Date 112,306 Wilcox Feb. 28, 1871 1,822,936 Reichel Sept. 15, 1931 2,083,449 Inman June 8, 1937 2,373,701 Meredith Apr. 17, 1945 

